Automatic exchange-selector.



H. B. HOLMES & E. B. CRAFT. AUTOMATIC EXCHANGE SELECTOR.

V APPLICATION FILED JUNE 4. 1906. 970,821

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H. B. HOLMES & E. B. CRAFT. AUTOMATIC EXCHANGE SELECTOR. APPLICATION FILED JUNE 4, 1906.

Patented Sept. 20; 1910.

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AUTOMATIC EXCHANGE SELECTOR.

APPLICATION FILED JUNE 4, 1906.

970, 2 1 I Patented Sept- 20, 1910.

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Patented Sept. 20, 1910.

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HOWARDB. HOLMES, OF PARK RIDGE, AND EDWARD B. CRAFT, OF WILMETTE, ILLI- NOIS, ASSIGNORS T- WESTERN ELECTRIC COMPANY, OF CHICAGO, ILLINOIS. A COR- PORATION OF ILLINOIS.

AUTOMATIC EXCHANGE-SELECTOR Specification of Letters Patent. Patented Sept. 20, 1910- Application filed June 4, 1906. Serial NO. 320,035.

To all whom it may concern:

lle it known that we, HOWARD B. HOLMES and EDWARD B. CRAFT, citizens of the United States, residing at Park Ridge and Wilmette, respectively,.in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Automatic.

llxelninge-Selectors, of which the following is a full, clear, concise, and exact description. ()ur invention relates to an automatic telephone exchange selector for effecting the interconnection of different lines terminating at the central exchange, and its object is to provide an improved and efficient device for accomplishing such interconnection with rapidity.

Our invention contemplates a selector carrying theterminals of the lines in the exchange and provided with a movable selector arm adapted to sweep over said terminals in long and short steps, respectively. A source 'of mechanical power is provided, such as a continuously rotating shaft, an electromagnetic clutch controlling the movement of said brush with the shaft in long steps over the terminals. lllectromagnetic mechanism is "arranged to step the brush in short steps over the terminals.

'e will describe our invcutionf more particularly by reference to the accompanying drawings, which represent the preferred enibod-iment thereof, reserving for the append- -ed claims a statement of the parts, improvements and combinations which we deem novel with us.

In the drawings, Figure 1 is a plan view of a selector embodying our invention; F 2 is a side elevation of the selector, partially in section; Fig. 3 is a vertical sectional view on line 3-3 of Fig. 1; Fig. 4 is'a bottom view of the short-step ratchet; Fig. 5 is a detail plan view of the long-step ratchet; Fig. 6 is a bottom view of the selector; Fig. 7 is a detail plan view of the spring adjustim plate; and Fig. 8 is a plan sectional detail on line S--8 of Fig. 3.

The same letters of reference are used to designate-the same parts throughout the different figures.

The line. terminals a, a, o of the-lines are mounted upon an insulating ring or supporting plate I) secured to the selector frame A, a movable contact arm 0 being provided in association with said terminals, carrying brushes 0', c 0 adapted to on age the terminals a, a, a respectively. he arm a is carrled by a ratchet d loosely mounted upon a sleeve 6 loosely mounted in turn upon a shaft 1 journaled in the frame A of the selector, said shaft carrying a pulley f" whereby it may be rotated. A ratchet g is rigidly secured to said sleeve, said ratchet carrying a pin 9' adapted to ride in a slot (1' in the ratchet d, a spring 72. connecting said The core a" is connected with the pole piece 2' of the magnet, which is provided with an.

annular flange 2' overhanging the magnet helix '5, the rim of said flange forming the polar face of said magnet. An armature preferably in the form of an annular disk, isspliued to the shaft before the polar face of the magnet. Thus when the armature 2' is attracted the sleeve 0 is caused to rotate with thc'shaft f.

The ratchet is arranged to advance the selector arm I in long steps over the line terminals, preferal'ily 10 terminals at a step, and is provided with long teeth and a retaining pawl I mounted upon the face plate A, said pawl being normally held by a suitable spring g against the teeth 9 an electromagnet g being mounted on the rear of said plate with its pole projecting through said plate in position to act, when energized, upon said pawl, to remove the same from on gagement with the teeth g". Thus on a hundred line exchange selector, such as illustrated, one hundred sets of terminals would be provided; the ratchet 9 would have ten operating teeth and the ratchet- (Z one hundred operating teeth.

The ratchet d is arranged to be operated independently of ratchet g to advance the arm 0 in short steps over the terminals, preferably from one set of terminals to the next.

The ratchet cl is provided with a stepping The said clutch,

upon the front'of said plate. When the ratchet (Z is operated by pawl (F, the pin g of ratchet g rides in the slot d in ratchet d without aiiecting the ratchet 9 until the pin strikes the wall (1* of slot 0Z. Thus if line 49 were desired, the tens ratchet would be operated to advance the contact arm 0 in four long steps to the terminals of line 40, and the ratchet d thereupon operated nine times to advance the arm to the terminals of line 49.

The ratchet (Z is provided with a retainlng pawl Z carried by the armature Z of a magnet Z mounted upon the rear of the face plate A, the pole Z of said magnet projecting through said plate in position to act on said armature. A spring Z normally maintains the pawl Z in engagement with said ratchet.

A springm is provided'for moving the sleeve and ratchets to return-the contact arm 0 to normal position when the retaining pawls are withdrawn by their magnets from ratchets d, g. Said spring we encircles the sleeve 6, being connected at one end to the plate A, and at the other end to a torsionadjustii'ig disk in." loosely mounted upon the sleeve e. Said disk is provided with a num ber of slots m m, a setbolt on being adapted when the disk is adjusted to pass through one of theseveral slots m into the threaded hole in the plate at which is in turn secured to the shell of the magnetic clutch by screws m m A brake is provided for the sleeve e adapted to be appliedas the arm reaches its normal position, said brake preferably comprising a brake shoe n pivoted torthe frame A alongside the flange 2' of the clutch, and carrying a spring a adapted as thecontact arm 0 approaches normal position to be engaged by a pin a carried by the pole piece 6 of the clutch, to graduall force said brake shoe against the flange 2' o the clutch. With this arrangement, the arm 0 is caused to come properly to rest against its stop 0, and recoil prevented. l

The operation of the selector shown is as followsz-The retaining pawls and g being normally incngagement with their re spective 1'atchets,'t-he electromagnetic clutch iisexcited intermittently a number of times corresponding to the numbefot long steps which it is desired to take, each excitation of the clutch being of a duration'sufiicient to insure the operative connection or coupling of tliepower'shaft f to the long step ratchet 17 or such an interval of time that the ratchet will be advanced one tooth, or such clutch 2" may be energized continuously for .for advancing the same in sweat a length of time sufficient to cause the ratchet to be continuously advanced the re"- quired number of teeth. hen the brushcarrier arm '0 has thus been advanced the required number of long steps the clutch magnet 2' is deenergized. The stepping magnet k is then intermittently excited a number of times corresponding to thenumber of short steps which it is desired the brush carrier arm shall take. Each excitation of the stepping magnet It causes the pawl (Z to advance the short step ratchet (Z one step, this further movement being independent of the long step ratchet g, which remains stationary. This further advance is against the tension of the spring h connecting the two ratchets, said spring normally holding the short step ratchet (Z at the rearward limit of its relative movement with respect to ratchet 9, so that the first movement of the loiig step ratchet 9 will cause the short step ratchet d to move therewith, the two being then in fixed relation.

When the retaining magnets l and g are excited, the retaining pawls Z and g are withdrawn from engagement with their respective ratchets, whereupon the spring [1, restores ratchet (l to its normal position relative to ratchet g, and spring-m returns both ratchets and the brush carrier arm to normal position.

We claim:

1. In a selector, the combination with stationary line terminals and'a movable brush carrier havingbrushes which it is adapted to trail over said line'terminals, a ratchet wheel moving with said brush carrier, electromagnetic stepping mechanism vfor advancing said second ratchet wheel operatively connected to advance said brush carrier in long steps, said first mentioned ratchetbeing mounted to have an advance movement independentof the long step ratchet, means for limiting said independent. advance movement and electromagnetic mechanism for advancing said long step ratchet.

2. In a selector, the combination witha movable brush carrier and a ratchet wheel short steps, a sec ond ratchet wheel mounted coaxially with the first ratchet and rotatable relatively thereto, a connection adapted to cause the first mentioned ratchet and brush carrier to be advanced by the advance movement of the second ratchet, said first ratchetbeing mounted to have-a further advance movement independent of the second ratchet, a stop for limiting said independent advance movement,

ratchet wheel in short steps, a

and separate electromagnetic stepping mechanisms for advancing the respective ratchets.

3. In an. automatic tele the combination with the hue terminals,-of acontact brush adapted to sweep over said hone exchange,

terminals, a continuously rotating shaft, a

ratchet loosely mounted on said shaft adapted to advance said brush, and electromagnetic mechanism for securing said ratchet to the shaft to rotate therewith.

4. In an automatic telephone exchange selector, the combination with stationary line terminals, of a contact brush adapted to sweep over said terminals, a continuously rotating shaft, a ratchet loosely mounted on said shaft adapted to advance said brush, an electromagnetically controlled retaining pawl for said ratchet, electromagnetic mech anism for causing said ratchet to rotate with said shaft, and mechanism adapted to restore said ratchet and brush.

5. In an automatic telephone exchange selector, the combination with the line terminals, of a contact crush adapted to sweep over said terminals, a continuously rotating shaft, a sleeve loosely mounted on said shaft, adapted to effect the advance of said brush over said-terminals, and a magnetic clutch adapted to cause said sleeve to rotate with said shaft.

6. In an automatic telephone exchange select-or, the combination with the line terminals, of a contact brush therefor, a continuously rotating shaft, a sleeve loosely mounted on said shaft adapted to advance said brush over said terminals, a magnet carried by said sleeve, and an armature therefor splined to rotate with said shaft; whereby when said armature is attracted the sleeve is caused to rotate with said shaft.

7. In an automatic telephone exchange selector, the combination with the line terminals, of a contact brush therefor, mechanical means for advancing said brush in long steps over said terminals, an electromagnetic clutch controlling said means, and electromagnetic mechanism adapted to advance said brush in short steps.

8. In an automatic telephone exchange selector, the combination with line terminals, of a contact brush therefor, a continuously rotating shaft, a magnetic clutch for causing said brush to move with said shaft in long steps over said terminals, and electromagnetically operated mechanism for advancing said brush in short steps over said terminals.

9. In an automatic telephone exchange selector, the combination with the line ter minals, of a contact brush therefor, a continuously rotating shaft, a ratchet wheel loosely mounted thereon adapted to step said brush in long steps over said terminals, a magnetic clutch for causing said ratchet to rotate with said shaft, and an electromagnetically operated ratchet wheel for advancing said brush in short steps over said terminals.

10. In a selector, the combination with stationary terminals and a movable brush carrier having brushes adapted to trail over said terminals, a short step ratchet adapted to advance said brush carrier, a long step ratchet adapted to advance the first mew tioned ratchet and the brush carrier in long steps, said short step ratchet also having an advance movement independent-of the advance of said long step ratchet, independent means for retaining the respective ratchets in their advanced posit-ions, an electromagnet, a stepping pawl actuated thereby for advancing the short step ratchet, a rotating power shaft, and an electromagnetic clutch adapted to couple said power shaft to said long step ratchet, substantiall as set forth.

11. In an automatic telep one exchange selector, the combination with the line terminals, of a contactbrush therefor, a short step ratchet carrying said brush, a long step ratchet, a pin carried thereby riding in a slot in said short step ratchet, means for operating said long step ratchet to cause said pin to advance said other ratchet and brush in long steps, and step by step means for independently operating said short step ratchet, said pin riding in said slot without affecting said long step ratchet.

12. In an automatic telephone exchange selector, the combination with the line terminalsfof a contact brush therefor, a continuously rotating shaft, a sleeve loosely mounted thereon, a long step ratchet carried on said sleeve, a pin carried by said ratchet, a short step ratchet loosely mounted on said sleeve and having a slot therein in which said pin rides, said ratchet carrying said contact brush, a magnetic clutch for connecting said sleeve to said'shaft to rotate therewith and operate said long step ratchet, said ratchet causing said pin to move the other ratchet and brush in long steps, and electromagnetic mechanism for independently operating'said short step ratchet, said pin riding in said slot without affecting said long step ratchet.

13. In an automatic telephone exchange selector, the combination with the line terminals, of a contact brush therefor, a ratchet for advancing said brush in long steps over said terminals, a continuousfy rotating shaft, 115 a clutch for connecting said ratchet with said shaft to rotate therewith, an elcctromagnetically operated ratchet for advancing said brush in short steps over said terminals, electromagnetically operated retaining pawls 120 for said ratchets, and mechanism for restor ing said ratchets and brush to normal position.

14. In an automatic telephone exchange selector, the combination with the line termi- 125 nals, of a movable contact brush therefor, 21- .-ontinuously rotating shaft, and an electromagnetic clutch controlling the connection of said brush with said shaft, said clutch comprising an electromagnet connected with 130 said brush and having a pole piece provided with an annular flange overhanging the magnet helix, and an armature'splined to said shaft before said flange.

15. In an automatic telephone exchange selector, the combination with the line ter minals, of a movable contact brush therefor, a continuously rotating. shaft, a sleeve loosely mounted on saidshaft adapted whenrotated to efiectthe movement of said brush, and an. electromagnetic clutch controlling the connection of said sleeve with said shaft, said clutch comprisin a magnet having a core secured to said s eeve, a pole piece secured to said core and having an annular flange overhanging the magnet helix, and an annular armature splined to the shaft before the polar face formed by the rim of said.

flange.

16. In an automatic telephone exchange selector, the combination with the line terminals, of a movable contact brush therefor, mechanical means for advancing said brush over said terminals, an electrorna netic clutch controlling said means, means or restoring said brush, and a brake therefor operated as said arm reaches its normal position.

17. In an automatic telephone exchange selector, the combination with the line ter minals, of a movable'contact brush therefor,

a continuously rotating shaft, a ratchet loosely mounted on said shaft for moving said brush over said terminals, an electromagnetic clutch' for connecting said ratchet with the shaft to move therewith, one member of said'clutch being connected to said ratchet, and the other member being secured to said shaft, an electromagnetically conand adapted to be moved by said first mentioned ratchet, an electromagnetic clutch for connecting said sleeve with said shaft, said clutch comprising a magnet secured to said sleeve and! having a pole piece provided with an annular flange overhanging the magnet helix, and an armature splined to said shaft before said flange, said clutch when oper ated mgving said first mentioned ratchet to advance the brush in long steps, means for independently operating the second mentioned ratchet to advance the brush in short steps, electroniagn'etically controlled retaining pawls for said ratchets, a spring for moving the sleeve to restore said ratchets and brush, a brakeshoe for. the annular fiange'oi said clutch member, a pin carried by said pole adapted as the brush reaches normal position to engage a portion of said brake and clamp it against said flange.

In witness whereof, we hereunto subscribe our names thisBlst day of May A. D, 1906. Y HOWARD B. HGLMES;

EDWARD B. CRAFT.

Witnesses:

1 ROY. T. ALLoWAY,

CLARENCE A. 006cm. 

